The only homekeyboard with additiv synthesis I know. This maschine was total under rated. You could produce so good NED Synclavier sounds with it. But the sound was rather thin without the built in chorus FX

Klangbeispiel / Soundclip

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(13.3 Mb .wav file of Seiko + a bit delay)

This is one single sound. Only the attack and release spectrum are defined. The main envelope mode is a decaying one. So there are three specrums called in a sequence with an overall decaying shape. First you hear a bell like attack that fades into a second, silent spectrum. Then the cross fade from the silent spectrum into the thrid spectrum gives another attack like sound. This is not a coloration by the delay causing two attacks!